If you do not keep up with your microwave, cleaning it can be difficult. It can seem like an impossible task, especially when you scrub and it just doesn't want to come clean. For that reason, I find that it's more helpful when you spray the microwave before you start cleaning anything else in the kitchen. And, if the microwave rests above the stove, just spray that down too. You're going to drop everything down onto the stove anyway. That way you soak the two dirtiest (in my kitchen, anyway) appliances so they should both be easier to clean when you get to them. Let (those) sit as you clean the rest of the kitchen. When you do get to the microwave, hopefully the cleaner did a good job of loosening up whatever was stuck on it. Now, sadly it's not always that easy. You can spray it, let it soak and scrub it as hard as you'd like and some things still just Won't.Come.Off. For that I have a trick that I learned years ago. Find a cup- something microwave safe, fill it with water and heat it in the microwave for 10-15 minutes. The steam should loosen up the last of the gunk. You can spray it down after, if you want. Then take your sponge and scrub away. You should then be looking at a sparkling clean microwave. Sometimes failure to upkeep causes permanent stains that settle into the plastic and cannot be removed by normal household cleaners. That requires restoration work and HD Cleaning does not offer that service. Or, you can just get a new microwave. But if you're like me and I know I can't get the stain out, I just ignore it and go about my business. It's irritating, but eh. I'll buy a new microwave when the current one stops working. For those that have a maid service clean their home, clean every once in a while between cleanings. Ideally you want to disinfect regularly, considering you put your food in there. That also helps keep stains from, well, staining the surface and your microwave looks great.